1. Technical Field
The present invention relates to a liquid ejecting head, a liquid ejecting apparatus, and a piezoelectric device.
2. Related Art
In the related art, as a representative example of a liquid ejecting head which discharges liquid droplets, an ink jet recording head which discharges ink has been known. As the ink jet recording head, for example, an ink jet recording head has been known in which a piezoelectric element, which is configured to have a lower electrode, a piezoelectric layer, and a upper electrode, is formed on a vibration plate provided on one surface of a flow channel forming substrate, the lower electrode is a separate electrode formed corresponding to each pressure generating chamber, and an upper electrode is a common electrode formed throughout a plurality of the pressure generating chambers.
As such a recording head, a recording head is proposed in which an upper surface and an end surface of the piezoelectric layer in a region facing the pressure generating chamber is covered with the upper electrode (common electrode), and a distance d1 between an upper surface of the lower electrode (separated electrode) and an upper surface of the piezoelectric layer and a distance d2 between an end surface of the lower electrode and an end surface of the piezoelectric layer satisfy a relationship of d2≧d1 (for example, referring to JP-A-2009-172878).
However, there is a strong demand for a recording head that realizes both securing reliability and excellent displacement properties on the basis of a background of miniaturizing a liquid ejecting head in recent. As disclosed in JP-A-2009-172878, in the recording head in which a lower electrode is a separated electrode and an upper electrode is a common electrode, the upper surface of the piezoelectric layer is generally flat in a manufacturing process; however, even such a recording head is required to be improved in terms of realizing both securing reliability and excellent displacement properties. Moreover, such a problem is not limited to the ink jet recording head, but also exists in the liquid ejecting head which discharges other liquid. In addition, the problem exists even in various piezoelectric devices in which a piezoelectric element is used in an actuator, a sensor, or the like.